Does which foods you eat matter in weight loss? I don't think any aspect of obesity and weight loss is more confusing, or more responsible for people's muddled thinking and poor choices in approaches to taking and keeping weight off. Most of the answers we're given to this question fall roughly into what seem like two sharply contrasting camps. The "it's all about the calories" camp (be warned, this link brings to you a nasty little article) suggests it doesn't really matter what you eat, you just need to eat small-enough amounts of it to not exceed the calories you're burning. The "eat healthier foods" camp suggests that you will lose weight if you emphasize certain foods over others--some push fruits and vegetables, others "less-processed" foods, others less-calorie-dense foods, others low carbs, others low fat, and so forth.
Here's my take on it. (I've been interviewing many, many respected experts in the obesity field and reading quite a lot of studies and articles, so I'm not entirely shooting from the hip here, or at least not more than anyone else. Consider this a synthesis of what I've been finding out.) The bottom line is that both camps are sort of right, but they're both a little misleading, too. It's true, you can lose weight eating anything if you keep portions small enough, and you can gain wait eating only vegetables if you eat enough of them. But most people are indeed more likely to keep the weight off if they lose it by emphasizing certain types of foods. That's because some foods more than others tend to push the various physiological and perhaps psychological buttons that will make it harder for you to keep control of your calorie intake. In the end, you'll still have to take in fewer calories than you're burning--but most people will find it easier to do that with some menus than with others.
So which foods should the would-be weight loser emphasize? There's a certain amount of disagreement on this question, to be sure, but a rough consensus of evidence and expert opinion favors cutting down significantly on sugar and refined carbs (like non-whole-wheat bread and pasta), taking it easy on fats (especially saturated fat, for other health reasons), eating good amounts of relatively lean protein (especially fish, chicken, and soy, prepared without much oil or butter, but beans, wheat gluten, egg whites, whey and pork can be good sources of lean protein, too), and eating lots of vegetables and reasonable amounts of fruit and other foods high in fiber. Most experts don't advocate ultra-low-carb diets (or even counsel cutting down much on complex carbs like whole-wheat foods), and most don't think an ultra-low-fat diet is worth the trouble. There are three main weight-control benefits to these recommended foods: They tend to be less calorie-dense, so they feel more filling per calorie and it's easier to meter how many calories you're taking in compared to a small, dense calorie-bomb like a piece of candy or fried chicken; they're less intensely stimulating to your pleasure systems, so you'll be less likely to feel compelled to pig out on them; and they tend to enter the bloodstream at reasonable rates, avoiding the blood-sugar spike-and-plummet effect you get from eating simple carbs that can lead to intense appetite swings.
Now having said all this, I'd like to point out that while eating "healthier" foods is a helpful and for most people important element of keeping weight off, I don't think it's necessarily the most important element, and it's absolutely not the only element, as is often implied by some weight-loss gurus. Most people will not be able to keep much if any weight off just by trying to take in more healthy food, if everything else they do and everything else that's going on around them otherwise remains the same. For most people keeping weight off requires a full-court press via a "behavioral" approach, something I'll be talking a lot about here and elsewhere. Part of that approach also involves finding out which healthier foods work best for you in terms of being as satisfying as possible without pushing your appetite and cravings buttons. And it also involves being smart about the way you introduce these foods into your daily menu and make enjoyable habits out of eating them, and about how you regulate your intake of these healthier foods as well as of those less-healthy foods you may also want to take in in order to have a satisfying diet.
Does all this seem like a lot of work to figure out, put into action and maintain? Well, it can be, but if you get good guidance it shouldn't be all that hard. Even if it is a lot of work, the benefits people get out of losing excess weight in terms of their health and how they feel almost always seem worth the trouble. And if you do the behavioral approach right, losing and keeping off weight--especially if you lose it slowly, and try don't lose a large percentage of your body weight--need never be hugely demanding or uncomfortable, and in fact ought to be highly satisfying and in many ways enjoyable.
Sunday, October 31, 2010
Thursday, October 28, 2010
Oh, behave!--and lose weight doing it, says JAMA study
The Journal of the American Medical Association just published a two-year diet study that I think is well worth looking at--and please remember it the next time you read about how the seriously overweight can't lose weight and keep it off without bariatric surgery or drugs because they're programmed by their genes to be obese. What I especially liked about this study was that rather than focusing on gimmicky diets that call for nearly altogether cutting out some food group (e.g. carbs or fat), or loading up on some type of food (e.g. dairy, as pushed in another recently published study getting some press), or pushing significant calorie deprivation, it instead focused on a "behavioral" approach--that is, in educating participants in how to establish healthier, sensible, sustainable eating and exercise habits, and in providing ongoing support to encourage them to stick with the program. It was also a randomized controlled trial--the obese women who participated were randomly assigned to a "normal care" group that got fairly minimal support, or one of two groups that got much higher levels of support as follows:
The diet component of the program consisted of a nutritionally adequate, low-fat (20%-30% of energy), reduced-energy diet (typically 1200-2000 kcal/d) that included prepackaged prepared food items with increased amounts of vegetables and fruits to reduce the energy density of the diet. The approach was tailored so that participants could choose regular foods when preferred. Participants were encouraged during the initial period to follow a menu plan with prepackaged foods, which would provide 42% to 68% of energy for those who choose not to deviate from the plan. Regular foods, such as vegetables, fruit, cereal or grain products, low-fat dairy products, lean meat or the equivalent, and unsaturated fat sources were recommended to achieve the total prescribed energy intake. Over time, participants were transitioned to a meal plan based mainly on food not provided by the commercial program, although participants could choose to include 1 prepackaged meal per day during weight loss maintenance. Prepared foods and counselors were provided by Jenny Craig Inc (Carlsbad, California).
Increased physical activity was another program component; the goal was 30 minutes of physical activity on 5 or more days per week. Program material and counseling addressed attitudes about weight, food, and physical activity and included recipes and guidance for eating in restaurants, CDs and DVDs to increase physical activity, and online tools and support.
And what do you know, the participants who got the real treatments took off weight and by the end of the two years had kept it off.
By study end, more than half in either intervention group....had a weight loss of at least 5% compared with 29%...of usual care participants.... More than twice the proportion of participants in the center-based and telephone-based intervention groups compared with participants in the usual care group...had a weight loss of 10% or more of baseline weight at 24 months....
As with all diet studies, there's plenty to be wary of, too. It was funded (but not run) by for-profit weight-loss-program company Jenny Craig, which also supplied pre-packaged meals for the studies, and bias toward the funders may well have crept in there somewhere. Two years is typically taken as a standard for proof that a diet intervention helps keep weight off, but obviously it doesn't necessarily tell you how the participants will fare in the next two, or ten or forty years, and weight-losers, like smokers, need to be in it for the long haul in order to really raise their chances of having a long, healthy life, not just long enough to look good for their high-school reunion. The reliance on free pre-packaged food is a somewhat unrealistic model for the real world--though not completely unrealistic if we as a nation start getting more serious, as we should, about helping the obese get healthier. The treatment participants got $25 for showing up for clinic visits--getting paid to lose weight is a hot idea these days, but I don't think smallish payments make a big difference over the long term and fear it just confuses the issue. As the study authors themselves point out, one always has to wonder if the people who participate in a diet study are representative of the population, for example in terms of level of motivation and commitment. But on the whole, I thought the diet interventions were smart, and doable on a large scale in the real world, and it was great to see them produce these impressive results in what seems a relatively careful study.
It also didn't surprise me in the least--behavioral approaches to weight loss, including Weight Watchers, have been doing pretty well in studies on a fairly consistent basis for decades, unlike most other approaches. So let's support more people who need to lose weight to be healthy in eschewing gimmicky and unsustainable diets, and in ignoring the toxic claims that they're genetically incapable of benefiting from any non-surgical, non-pharmaceutical intervention, and instead make it easier for them to get access to comprehensive behaviorally oriented weight-loss programs designed to take modest amounts of weight off gradually, comfortably and forever.
Tuesday, October 26, 2010
Doctors and dieting; and measuring calorie burn
Nicholas Bakalar has a good article about physicians' efforts to encourage patient weight loss in the New York Times "Science Times" section. Bakalar is one of the most careful writers at the Times when it comes to avoiding flashy medical findings that aren't likely to hold up, as well in making a point of looking for and clearly reporting on the limitations of the studies he covers. You wouldn't think those would be unusual traits in science journalists, and especially in Times reporters, but they are. (I should also mention I've met Bakalar a few times and consider him a friend, but my admiration for his work pre-dates my knowing him.)
Bakalar's piece makes two important points: physicians normally have little luck in getting patients to lose weight, and physicians tend to have more impact when instead of trying to push a patient into losing weight they instead work with the patient to try to figure out together what to do about the problem. I've been researching both of these issues for my ongoing obesity projects, and Bakalar's article is spot on with regard to both of them. I've asked dozens of physicians how many patients they've managed to convince to lose weight, and the answer is pretty much always just about zero. And the idea of working with patients to come up with an appropriate plan that focuses in part on helping patients to recognize and deal with their lack of motivation, and in part in figuring out what actions can be taken that are realistic for whatever level of motivation they have, is a critical part of a behavioral approach to weight loss. Something I'll be saying a lot more about in this blog and elsewhere is the fact that the behavioral approach, while backed by a lot of evidence, made famous by Weight Watchers and pushed by many highly credible experts and public health officials, is largely ignored by most of the overweight public as well as by most physicians and obesity researchers--and I think it's a big reason we keep getting bigger.
Separately, here's a piece, this one in Canada's Globe and Mail, that hits on a another point I've become very interested in: the terrible job that people and devices do in measuring calories burned when exercising. I'll have more to say about this soon.
Bakalar's piece makes two important points: physicians normally have little luck in getting patients to lose weight, and physicians tend to have more impact when instead of trying to push a patient into losing weight they instead work with the patient to try to figure out together what to do about the problem. I've been researching both of these issues for my ongoing obesity projects, and Bakalar's article is spot on with regard to both of them. I've asked dozens of physicians how many patients they've managed to convince to lose weight, and the answer is pretty much always just about zero. And the idea of working with patients to come up with an appropriate plan that focuses in part on helping patients to recognize and deal with their lack of motivation, and in part in figuring out what actions can be taken that are realistic for whatever level of motivation they have, is a critical part of a behavioral approach to weight loss. Something I'll be saying a lot more about in this blog and elsewhere is the fact that the behavioral approach, while backed by a lot of evidence, made famous by Weight Watchers and pushed by many highly credible experts and public health officials, is largely ignored by most of the overweight public as well as by most physicians and obesity researchers--and I think it's a big reason we keep getting bigger.
Separately, here's a piece, this one in Canada's Globe and Mail, that hits on a another point I've become very interested in: the terrible job that people and devices do in measuring calories burned when exercising. I'll have more to say about this soon.
Monday, October 25, 2010
Should the public be told about the trouble with medical research?
Among the reaction to my Atlantic article there has of course been a certain amount of skepticism and criticism. Some of the criticism has been perfectly fair and insightful, pointing out the ways in which I or Ioannidis (the physician-researcher I profile in the article who has documented and analyzed the high wrongness rate in medical research) might ourselves be biased, and might be spinning some aspects of the story. I touch on this problem in the article, and have a whole chapter on it in the book, and I have no interest in denying that my own bias and sloppiness (as well as those of the people I interview and those of my editors) may skew things.
I generally welcome criticism, and usually don't respond to it--I figured I had my say--except as part of a formal response to comments submitted to the publication that ran the article. But I saw a blog post today that I think calls for a bit of a response. The post, by the physician-researcher David Gorski (whom I actually briefly quote in the Atlantic article), echoes posts in other blogs from a few people in or close to the medical community in essentially suggesting that the problems with research that Ioannidis has uncovered and that I report on in the article aren't really big problems; rather, they're just an acceptable part of the nature of research. I don't think so. Bias and sloppiness may be routine and perhaps inevitable even among top researchers, but that doesn't mean we shouldn't be made aware of the extent of the problems and the toll it takes on the credibility of medical findings--and the vast majority of researchers seem to agree, to judge by most of what has been posted in response to the article. Gorski's post also states that we should focus on the fact that (as I report in the article) 90 percent of large randomized controlled trials tend to hold up, and not pay much attention to the fact that other types of studies sink to levels as low 10 percent rightness and even lower. This is to me a shocking argument, considering that large RCTs make up a tiny percentage of the studies that fill journals, make headlines and influence treatment and lifestyle decisions.
Finally, the post argues that everyone should put their energy not into looking into the problems with mainstream medical research, but rather into the poor or non-existent science behind alternative medicine--and that we should keep our mouths shut about whatever problems we do find with mainstream medicine because it only gives ammunition to the alternative medicine crowd. Once again, I have to strongly disagree. People who are drawn to alternative medicine have already proven themselves essentially either uninterested in or incapable of assessing scientific evidence, and when researchers like Gorski rant and rave about alternative medicine they're really just preaching to the choir, as is clear from the comments that appear under his post. In fact, compare the nearly unanimous point of view in these comments to those that appear almost anywhere else in response to the Atlantic article--Gorski's fans clearly have their minds made up about people who criticize mainstream medical research, and they don't even actually have to read the criticism themselves to feel comfortable commenting dismissively and authoritatively on it. Some of the comments, following Gorski's lead, include ad hominem attacks on me that are based entirely on sloppy and mostly incorrect assumptions about my background.
Unlike the well-known absence (with a few exceptions) of good science behind alternative medicine, the serious problems with mainstream medical research have largely been unknown outside of the medical community itself. I believe the public has a right to hear about them, and to judge by the reaction the public seems quite interested in hearing about them. I quote Ioannidis in the article as pointing out that if mainstream medical science tries to keep quiet about its problems and limitations, then it is doing what it accuses alternative medicine of doing--misleading the public. I'm glad Gorski and his fans represent a small minority of the medical community in being unwilling to own up to and communicate these problems--see, for example, what the British Medical Journal had to say about my book--and in focusing instead on endlessly recycling the same old complaints about alternative medicine because it makes them look good in comparison.
And for the record: Along the way, Gorski belches out the sarcasm-and-bile-drenched claim that my earlier post on this blog relating to quack autism researcher Andrew Wakefield reflects my refusal to recognize that Wakefield was wrong. That's just plain silly. The point of the post was that the outing of a rare, gross fraud like Wakefield distracts from the more widespread, routine problems in medical research trustworthiness. I think I was pretty clear about that, but judge for yourself. I happen to be a little sensitive to the suggestion that I support quack autism research, because two members of my immediate family work with children with autism, relying solely on the treatment that is the mainstream standard of care, applied behavior analysis. I know quite a bit about autism quackery, actually. I just didn't think the intelligent readers of this blog needed me to rant and rave, Gorski-style, about an obvious and blatant charlatan who had long been making global headlines for his misdeeds. (And my Wakefield post linked to an article that described the misdeeds at length, though I just now changed the link to point to a similar article because the original is no longer online.) Considering that he passes himself off as the champion of objectivity, facts and reason, Gorski seems surprisingly comfortable distorting the facts to fit his nearly undisguised biases. But maybe we should be grateful for undisguised biases--it's really the well-disguised ones we need to watch out for.
I generally welcome criticism, and usually don't respond to it--I figured I had my say--except as part of a formal response to comments submitted to the publication that ran the article. But I saw a blog post today that I think calls for a bit of a response. The post, by the physician-researcher David Gorski (whom I actually briefly quote in the Atlantic article), echoes posts in other blogs from a few people in or close to the medical community in essentially suggesting that the problems with research that Ioannidis has uncovered and that I report on in the article aren't really big problems; rather, they're just an acceptable part of the nature of research. I don't think so. Bias and sloppiness may be routine and perhaps inevitable even among top researchers, but that doesn't mean we shouldn't be made aware of the extent of the problems and the toll it takes on the credibility of medical findings--and the vast majority of researchers seem to agree, to judge by most of what has been posted in response to the article. Gorski's post also states that we should focus on the fact that (as I report in the article) 90 percent of large randomized controlled trials tend to hold up, and not pay much attention to the fact that other types of studies sink to levels as low 10 percent rightness and even lower. This is to me a shocking argument, considering that large RCTs make up a tiny percentage of the studies that fill journals, make headlines and influence treatment and lifestyle decisions.
Finally, the post argues that everyone should put their energy not into looking into the problems with mainstream medical research, but rather into the poor or non-existent science behind alternative medicine--and that we should keep our mouths shut about whatever problems we do find with mainstream medicine because it only gives ammunition to the alternative medicine crowd. Once again, I have to strongly disagree. People who are drawn to alternative medicine have already proven themselves essentially either uninterested in or incapable of assessing scientific evidence, and when researchers like Gorski rant and rave about alternative medicine they're really just preaching to the choir, as is clear from the comments that appear under his post. In fact, compare the nearly unanimous point of view in these comments to those that appear almost anywhere else in response to the Atlantic article--Gorski's fans clearly have their minds made up about people who criticize mainstream medical research, and they don't even actually have to read the criticism themselves to feel comfortable commenting dismissively and authoritatively on it. Some of the comments, following Gorski's lead, include ad hominem attacks on me that are based entirely on sloppy and mostly incorrect assumptions about my background.
Unlike the well-known absence (with a few exceptions) of good science behind alternative medicine, the serious problems with mainstream medical research have largely been unknown outside of the medical community itself. I believe the public has a right to hear about them, and to judge by the reaction the public seems quite interested in hearing about them. I quote Ioannidis in the article as pointing out that if mainstream medical science tries to keep quiet about its problems and limitations, then it is doing what it accuses alternative medicine of doing--misleading the public. I'm glad Gorski and his fans represent a small minority of the medical community in being unwilling to own up to and communicate these problems--see, for example, what the British Medical Journal had to say about my book--and in focusing instead on endlessly recycling the same old complaints about alternative medicine because it makes them look good in comparison.
And for the record: Along the way, Gorski belches out the sarcasm-and-bile-drenched claim that my earlier post on this blog relating to quack autism researcher Andrew Wakefield reflects my refusal to recognize that Wakefield was wrong. That's just plain silly. The point of the post was that the outing of a rare, gross fraud like Wakefield distracts from the more widespread, routine problems in medical research trustworthiness. I think I was pretty clear about that, but judge for yourself. I happen to be a little sensitive to the suggestion that I support quack autism research, because two members of my immediate family work with children with autism, relying solely on the treatment that is the mainstream standard of care, applied behavior analysis. I know quite a bit about autism quackery, actually. I just didn't think the intelligent readers of this blog needed me to rant and rave, Gorski-style, about an obvious and blatant charlatan who had long been making global headlines for his misdeeds. (And my Wakefield post linked to an article that described the misdeeds at length, though I just now changed the link to point to a similar article because the original is no longer online.) Considering that he passes himself off as the champion of objectivity, facts and reason, Gorski seems surprisingly comfortable distorting the facts to fit his nearly undisguised biases. But maybe we should be grateful for undisguised biases--it's really the well-disguised ones we need to watch out for.